Mabinogion Syllabification: (Mab·i·no·gi·on)Pronunciation: /ˌmabəˈnôgēən, -ˈnōgēən/Definition of Mabinogion a collection of Welsh tales of the 11th-13th centuries, dealing with Celtic legends and mythology. Origin:from Welsh Mabinogi 'instruction for young bards'Mabinogion in other Oxford dictionaries Definition of Mabinogion in the British & World English dictionary